Stability and structure of adaptive self-organized supramolecular artificial water channels in lipid bilayers

Nanopores that efficiently and selectively transport water have been intensively studied at the nanoscale level. A key challenge relates to linking the nanoscale to the compound's macroscopic properties, which are hardly accessible at the smaller scale. Here we numerically investigate the influence of varying the dimensions of a self-assembled Imidazole I-quartet (I4) aggregate in lipid bilayers on the water permeation properties of these highly packed water channels. Quantitative transport studies reveal that water pathways in I4 crystal-like packing are not affected by small scaling factors, despite non-uniform contributions between central channels shielded from the bilayer and lateral, exposed channels. The permeation rate computed in simulations overestimates the experimental value by an order of magnitude, yet these in silico properties are very dependent on the force field parameters. The diversity of observed water pathways in such a small-scale in silico experiment yields some insights into modifying the current molecular designs in order to considerably improve water transport in scalable membranes.